Comparison of Cardiopulmonary Exercise Test Variables to Predict Adverse Events in Patients with Heart Failure.

Purpose: Given the rising burden of heart failure (HF), stratification of patients at increased risk for adverse events is critical. We aim to compare the predictive value of various maximal and submaximal cardiopulmonary exercise test (CPET) variables for adverse events in patients with HF.
Methods: 237 patients with HF (66 [58-73] years, 30% women, 70% HF with reduced ejection fraction) completed a CPET and had five years of follow-up. Baseline characteristics and clinical outcomes (all-cause mortality, major adverse cardiovascular events, and cardiovascular-related hospitalization) were extracted from electronic patient files. Receiver operating characteristics curves for maximal (e.g. peak VO2) and submaximal CPET variables (e.g. VE/VCO2 slope, cardiorespiratory optimal point (COP), VO2 at anaerobic threshold) were compared using the Akaike Information Criterion (AIC) method, whereas their calibration was assessed.
Results: 103 participants (43%) reached the composite endpoint, and 55 (23%) died. Percent predicted peak VO2 was the best predictor for adverse outcomes (AIC: 302.6) followed by COP (AIC: 304.3), and relative peak VO2 (mL/(kg·min), AIC: 304.4). Relative peak VO2 (AIC: 217.1) and COP (AIC: 224.4) were also among the three best predictors for mortality, together with absolute peak VO2 (ml/min, AIC: 220.5). A good calibration between observed and predicted event rate was observed for these variables.
Conclusions: Percent predicated and relative peak VO2 had the best predictive accuracy for adverse events and mortality, but the submaximal COP had a non-inferior predictive accuracy for adverse events in patients with HF. These findings highlight the potential of submaximal exercise testing in patients with HF.
Competing Interests: Conflict of Interest and Funding Source: This project is supported by an Eurostars Grant (E!114585). EB has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No [101064851]. All the authors have no conflicts of interest or financial ties to disclose.
(Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American College of Sports Medicine.)